Gripping-tongs.



'Nm 870,713. I PATBNTED NOV. 12, 1907.

A". GHRISTIANSON.

. GRIPPING TONGS. APPLIOATION FILED 110.22.1906.

ANDREW CHRISTIANSON, OF BUTLER, PENNSYLVANIA.

GRIPPING-TONGS.

Specification of Letters Patent.

Patented Nov. 12, 1907.

Application filed December 22.1906. Serial No. 349.181.

To all :whom it may concern:

Be it known that l, Anonsw (lnins'riANsoN, a resident ofB-utler, in the county of .liutler and State of Pennsylvania, have invented a new and useful lmprovement in Gripping-'l`ongs; and l do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to lifting mechanism, and especiallyto mechanism for use in mills and` manufacturing plants for the purpose of lifting, carrying and depositing various articles.

I 'lhe object of the invention is to provide mechanism of this character which operates entirely automatically for both engaging or gripping the article and for releasing the same, these results being accomplished by the mere act of raising and lowering the mechanism, such as by means of an ordinary crane.

The invention clailned and described herein operates upon the same generalprineiple as that described and, claimed in my application Serial No. 349,180 filed concurrently herewith, which said application embodies the invention generically, while this application describes and claims a modification of the form shown in said` companion application to illustrate the Igeneric invention.

,showing the mechanism in the position of gripping and lifting the article; and Fig. 4 is a central verticalscction of the mechanism taken on the line 4-4 Fig. l. The mechanism is shown in the drawings in the form p of tongs for the purpose of gripping a billet, har or other article 1 on the exterior thereof. As shown lthe mechanism comprises gripping or article-engaging jaws 2 g formed on levers which are pivoted at 4 to a suitable supporter frame 5. This frame or support comprises the two side plates 6 which are spaced apart as by means of the bottom spacing piece 7 and top spacing Apieces 8, so as to provide a space between said side plates for the jaw levers 3 and also for the suspending bar or member 9, 'which at its upper end is provided an`eye 10 or other suitable means for engaging the hook or chain of a crane, derrick or other suitable lift- Y ing mechanism.

To the upper ends vof the jaw levers 3 are pivotally l connected linksll whose inner ends are pivotally conslots 14 independently of the frame or jaw-supporting.V

member 5. The suspending bar or member 9 its lower end attached directly to the pin or shaft 12.

The principle of operation of the device depends upon carrying the jaws 2 alternately from the pin 12 and from the frame or support 5. It is evident that if no means further than described were employed the lifting of the device by means of the bar 9 would always act to suspend the jaws from the pin 12, thus causing an upward movement of said pin in the slots 14 and straightening out the toggle links l1, causing the jaws 2 to close and engage or grip the article l. This is in fact what occurs when the article is to be gripped, and the position shown in Fig. 3 in which the article is being carried.

In order to release the article and hold the jaws open so as to be in position for engaging another article the following means are providedz. Pivotally secured to the frame 5, as by means of a bolt 16, are a pair of oscillating plates 17, one on either side, which are provided with a pair of upwardly projecting arms 18 which extend up above the highest position of the pin 12, so as to prevent said plates from swinging too far in either direction, one of said arms being provided with a right angled portion 19 forming in effect a hook adapted in certain positions of the device to pass abovethe pin 12, as shown in Fig. l. ln this position obviously the lifting of the pin l2 by the bar 9 merely causes said pin to engage the hooks 19 and prevents the further upward movement of said pin relative to the other parts ofthe mechanism and thus prevents the toggle linksll from being straightened out. ln this position the jaws 2 are carried from the frame 5, plates 18 and hooks 1,9, so

that the jaws are held in open position.

The oscillation of the .plates 18 to alternately bring 4 the hooks 19 into and out of the path of movement of the pin 12 is effected by providing said plates with a pair of cam faces 20 and 21 separated by the projecting lportion 22 and forming the lower walls of openings 23 -in said plates.v Cooperating with these cam faces is a bolt or bar 24 which extends from side to side through suitable openings formed in the' side members 6 of the frame 5, and whose outer ends are connected by means of links or b ars 25 tothe ends of the pin 12.

The operation of the mechanism is as follows: The bar 9^will be' suspended from the-hook or chain of a crane, derrick or other suitable mechanism. We will suppose that the tongs are open, shown in Fig. 1, and in position to engage an article. In this position the plates 17 are in such position that the hooks 19 engage the pin 12, thus connecting the suspending member 9 to said plates, and through the same to the supporting member 5.0i the tong levers; Consequently in this position the tong levers arepractically carried by the frame 5 while the toggle links are held against straighttion. In this position the device is brought over the l article to be gripped and lifted. 'lhe mechanism is then lowered, the jaws passing down on either side of tongs to permit it to engage the article, orflto open the tongs to release the article. I believe I am the irst [to devise gripping tongs which operate automatically the article. In this downward movement the lower end of the jaw supporting frame or member 5 contacts with the article l and consequently its further downward movement is prevented. The suspending bar 9, however, is free to continue its downward movement, the pin l2 merely riding down in theslots 16. This downward movement of the piu forces the links 25 and bar 24 downwardly, and the latter strikes again st the cam faces 20 of the plates 17. Since these cam faces are inclined, this movement causes the links 25 to swing on the pin 12 to carry the bar 24 to the left, viewing Fig. 1, and causes it to push down on the cam faces 20 on the left-hand side ofthe vertical median line of the plates. As a consequence said' plates will be swung on .their pivots, toward the left, vcarrying the hooks 19 out ofthe path of movement of the pin-12. Consequently when the device is raised the bar 9 pulls on the pin l2 and as the latter is free to travel upwardly in the slots' 14 this causes thelinks l1 to straighten out suiiiciently to close the jaws on the'article before there is any lifting movement imparted to the frame 5. The result is that the jaws 2 are caused to engage and grip the article 1, the mechanism assuming the position shown in Fig. 3, in which the article is being carried.

To disengage the tongs from the article it is merely necessary to lower the mechanism. The downward movement will continue until the article strikes the iioor and becomes stationary and in the .further downward movement the frame 5 again contacts with the article and its further downward movement is arrested. The bar 9 and pin 12, however, continue to move downwardly, thus again carrying the bolt or bar 24 downwardly to engage the cam faces on the plates 17. In.

the swinging movement of these platestoward the left, as before' described, the projecting portions 22 of the cam 'faces were brought beyond the central or median line of the device, while in the lifting movement before described .the links 25 andbar 24 were by gravity swung back to the central or median line ofthe device.

' Consequently, in the second downward movement said bar 24 engag thecam faces 21 on the right hand `side of the device, and in its downward movement causes the plates 17 to swing in the opposite direction, that is, toward the right, viewing Fig. 1. -This lagain swings the hooks 19 into such position that-they will be in the path of movementof the pin l2. In the downward movement of the pin 12 the toggle links 1l were flexed,

and consequently the jaws 2 opened. Lifting the device causes the pin 12 to move upwardlyuntil it engagesrthe hook 19. V This occurs, however, before the toggles can straighten sufficiently to again grip the article and consequently the deviceis carried with the jaws held in open position 'and ready to engage another article, which Will be effected automatically by merely lowering the device as heretofore described.

It will be Aobserved that the tongs described operate entirely automatically, both to openand closeby the mere raising and lowering of the same. vIn this particular it is essentially different from any shop or mill tongs-heretofore devised in which, as far as I know, an attendant has always been required to either open the both to close and to open and which remain open until a new article is engaged.

While the tongs have been shown and described as provided with jaws which engage the article by a gripping action, it is obvious that they can be modified so as to be provided with openings for receiving lugs on the article (such as is the case with suspending and carrying devices for ingot molds or the like), or, vice versa, the tong jaws may beprovided with studs or projections te enter openings in the sides of the article. Inwneither of these cases would the tongs, strictly speaking, grip the article, but'would nevertheless engage the same. By the terms gripping and grippers as used in the claims herein made I intend to cover not only jaws which actually grip the article by a pinching action, but also such -modiications as 4 merely engage the article either by projections on the article or projections on the jaws.

What I claim isi 1. Lifting mechanism comprising in combination, lwork engaging members. u supporting member ou which said work engaging members are mounted, links arranged to actuate said work engaging members, suspending means having movement independently of said supporting member, means movable to two positions and arranged in one position to connect the suspending means and supporting member and in the other position togdisconnect the same, and connections actuated by the weight of the suspending means on relative movements between said suspending means' and the supporting member and arranged to positively move said connecting means alternately to the two positions. l

2. Lifting mechanism comprising,r in combination, work engaging. members, a supporting member .on which said work engaging members are mounted, links arranged to actuate said work engaging members, suspending means having movement independently of said supporting member, means carried by the supporting member and movable to two positions and arranged in one position,to conneet the suspending means and supporting member and lnv the other position to disconnect the same, and connections from the suspendingmeans and actuated by the weight of 11G the latter on relative vertical-movements between the same and the supporting member and arranged to posi# tively move said' connecting means alternately to its two positions.

YLifting mechanism comprising in combination, grip- 115 ping members, a support on which said grippers are pivotully mounted, links connected to said grippers, suspending, means connected to said links and having movement independently of the gripper support, means movable to two positions and arranged in one positionto connect the susi 120 pending means and gripper support and in the other position to disconnect the same, and connections actuated by the weight of thc suspending means on relative vertical movements between the same and the gripper support and :ii-ranged to positively muvo said connecting means` alterna tely to its two positions. l

4. Lifting mechanism comprising in combination, grip.- png members, a frame to which said gripper-s are pivotnll'yrconnecied. a suspending member having movement independently of said frame, links connecting said suspending member and grippers, a movable member having two I positions and arranged in one position to connect the suspending member and frame and inthe other position to disconnect the same'and provided withcam faces, and con- I neetions actuated by the weight of the suspending member on relative vertical movements between the` same and the frame and arranged to contact with said cams and thereby positively move snid movable member alternately to its two positions. I A

5. 'Lifting mechanismcomprlging in combination, grlp- 140 pers, a supporting frame on which saidgrippers are pivotaliy mounted, a suspending member having movement relatively to said frame, actuating connections between the suspending` member yand grippers, a swinging member mounted on the frame and movable to two positions and arranged in one position to connect the suspending .member and trame and in the other position to disconnect the same, and connections actuated by the weight of thc suspending member on relative vertical movements between the same and the frame and arranged to positively move said swinging member alternately to its two positions.

V6. Lifting mechanism. comprising in combination, work engaging levers, a fran'ie on which said levers are pivotally mounted, toggle links connected to the outer ends of said levers. suspending means connected to said links. a movable piece mounted on the frame and having two positions and arranged in one position to connect the frame and suspending means and in the other to disconnect the same and means actuated by the weight ofthe suspending. means on relative vertical movements between the same and the trame and arrangedto, positively move said mov-4 able piece alternately to its two positions.

7.`l'.lfting mechanism comprising in combination, gripping` levers, a frame on which 'said levers are pivotally mounted. suspending means having movement independently of said frame, actuating connections'between suspending means and gripping levers, a. movable member having two positions and arranged in one of said positions to connect the suspending means and frame, and-ln the other position to disconnect the same, and'connections includlng the cam faces and actuated by the weight of the suspending means` on relative vertical movements between the same and the frame andarranged to positively move said movable member alternately to its two positions.

8. Lifting mechanism, comprising in combination, work engaging levers,`a frame on which said levers are pivotally supported, links connected to the outer ends of the levers, suspending means to which the inner ends of the links are connected, a swinging member mounted on the trame and arranged to engage the suspending means, and means actuated from the links for positively swinging said piece to alternately engage and dlsengage'the suspending means.

9. Lifting mechanism comprising in combination, work engaging levers, s frame on which said levers are pivotally mounted, links connected to the outer ends of the.ie vers, suspending means connected to the inner ends of the links, a swinging member mounted on the frame and arranged to engage the suspending means, cam faces on said -swinglng piece, and a member actuated by the movement of the suspending means with relation to thc frame and arranged to engage said cam faces and alternately swing said piece to engage und disengage'sthe suspending menns.

Witnesses ltounwr C. 'ip'r'ri-m, J. R. Kunnen. 

